[TASK] Clean-up and update INSTALL.txt

- Update copyright year
- Include required module "fileinfo" in recommended section
- Add reference to recommended library FreeType 2
- Correct typo3.org deep links accordingly (T3O)

Change-Id: I067b2d930c1a6ffa15ea61f10723e29eb434f491
Resolves: #48541
Releases: 6.2
Reviewed-on: https://review.typo3.org/21064
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn